CVE-2005-0021 — Multiple buffer overflows in Exim before 4

Multiple buffer overflows in Exim before 4.43 may allow attackers to execute arbitrary code via (1) an IPv6 address with more than 8 components, as demonstrated using the -be command line option, which triggers an overflow in the host_aton function, or (2) the -bh command line op

01What is this vulnerability?

Multiple buffer overflows in Exim before 4.43 may allow attackers to execute arbitrary code via (1) an IPv6 address with more than 8 components, as demonstrated using the -be command line option, which triggers an overflow in the host_aton function, or (2) the -bh command line option or dnsdb PTR lookup, which triggers an overflow in the dns_build_reverse function.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2005-01-06T05:00:00.000Z
• Last modified: 2024-08-07T20:57:41.064Z

09References

• www.idefense.com — http://www.idefense.com/application/poi/display?id=179&type=vulnerabilities
• www.kb.cert.org — http://www.kb.cert.org/vuls/id/132992
• www.debian.org — http://www.debian.org/security/2005/dsa-635
• ftp6.us.freebsd.org — http://ftp6.us.freebsd.org/pub/mail/exim/ChangeLogs/ChangeLog-4.44
• www.debian.org — http://www.debian.org/security/2005/dsa-637
• www.idefense.com — http://www.idefense.com/application/poi/display?id=183&type=vulnerabilities
• www.redhat.com — http://www.redhat.com/support/errata/RHSA-2005-025.html
• security.gentoo.org — http://security.gentoo.org/glsa/glsa-200501-23.xml
• www.exim.org — http://www.exim.org/mail-archives/exim-users/Week-of-Mon-20050103/msg00028.html
• oval.cisecurity.org — https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3…